1. Field of the Invention
The present invention pertains to a patient interface device selection system, and, in particular, to a patient interface device selection system that employs 3-D models.
2. Description of the Related Art
Obstructive sleep apnea (OSA) is a condition that affects millions of people from around the world. OSA is characterized by disturbances or cessation in breathing during sleep. OSA episodes result from partial or complete blockage of airflow during sleep that lasts at least 10 seconds and often as long as 1 to 2 minutes. In a given night, people with moderate to severe apnea may experience complete or partial breathing disruptions as high as 200-500 per night. Because their sleep is constantly disrupted, they are deprived of the restorative sleep necessary for efficient functioning of body and mind. This sleep disorder has also been linked with hypertension, depression, stroke, cardiac arrhythmias, myocardial infarction and other cardiovascular disorders. OSA also causes excessive tiredness.
Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device, which is typically a nasal or nasal/oral mask, on the face of a patient to interface the ventilator or pressure support system with the airway of the patient so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient.
Typically, patient interface devices include a mask shell or frame having a cushion attached to the shell that contacts the surface of the patient. The mask shell and cushion are held in place by a headgear that wraps around the head of the patient. The mask and headgear form the patient interface assembly. A typical headgear includes flexible, adjustable straps that extend from the mask to attach the mask to the patient.
Because patient interface devices are typically worn for an extended period of time, a variety of concerns must be taken into consideration. For example, in providing CPAP to treat OSA, the patient normally wears the patient interface device all night long while he or she sleeps. One concern in such a situation is that the patient interface device is as comfortable as possible, otherwise the patient may avoid wearing the interface device, defeating the purpose of the prescribed pressure support therapy. Another concern is that an improperly fitted patient interface device can include gaps between the patient interface device and the patient that cause unwanted leakage. Thus, it is desirable to select a patient interface device that properly fits a patient.
A variety of different types or styles of patient interface devices are available. Additionally, a variety of different sizes of each type and style of patient interface device are available. Thus, the total number of distinct patient interface devices available to a patient can become quite large.
Caregiver's have generally assisted patients with the selection of a suitable patient interface device. The caregiver can take into account the patient's condition and preferences to narrow down the list of potential patient interface devices. The caregiver can also estimate the proper size of the patient interface device or have the patient try on several patient interface devices to determine the correct size. However, these methods can be time consuming and inaccurate.
US 2006/023228 A1 discloses a system and method providing a process for fabricating a facial mask to custom fit a patient's face for a comfortable fit for facilitating various medical procedures including the steps of generating a 3D data set to define a portion of a patient's face to be fitted with a custom mask, fabricating a patient's mask utilizing a patient's 3D facial data set, and fitting a patient with a custom fit facial mask for facilitating a desired medical procedure.
EP 1 116 492 A2 discloses a method in which a spatial record of the area of a user's face around mouth and nose is recorded. Based on the spatial record, a sealing lip section of a breathing mask is formed so that it is matched to an individual's record.
Accordingly, a need exists for improvement in ways to select a suitable patient interface device for a patient.